Other Risks: Long-term consumption, in excessive quantities, may give rise to problems such as insomnia, restlessness, annoyance, irritability, headaches, hypertension, abnormal heartbeat, loss of appetite, spasms, constipation, and acute addiction to caffeine. Many times, people who are addicted to caffeine do not feel normal without the substance and suffer from acute constipation, irritation, and lack of concentration in the absence of green tea.

It’s become such a fashionable beverage that, last summer, the New York Post ran a story about how Victoria’s Secret models were flocking to Cha Cha Matcha, a hipster spot fluent in the preparation of various matcha-based miracle potions. A search for where to get “matcha” in New York, New York on Yelp yielded some 1400 plus results. Even mass market coffee purveyors like Starbucks have made matcha their mantra, with a vast range of offerings to cash in on the craze.

Green tea leaves are initially processed by soaking in an alcohol solution, which may be further concentrated to various levels; byproducts of the process are also packaged and used. Extracts may be sold in liquid, powder, capsule, or tablet form.[4] Decaffeinated versions are also available.[9] Green tea extract supplements are accessible over the counter in various forms.[10]

Research shows that people who regularly drink green tea do not fall victim to common bacterial and viral infections as easily as those who do not add it to their diet. It boosts the immune system. The catechins, present in green tea, prevent bacteria and viruses from attaching themselves to cell walls in order to infect them. These catechins also counter the toxins released by microbes. This antimicrobial property also protects you from bad breath, dysentery, diarrhea, tooth decay, indigestion, flu, cough and cold, and colitis, all of which are caused by the microbial and fungal action.

Green tea has slightly more antioxidants compared to black tea, although both are still great sources. The ORAC value (antioxidant content) of brewed black tea is 1,128 while green tea is slightly higher at 1,253. Black tea and green tea both contain antioxidants, including polyphenols. Some research shows that green tea contains more than four times the catechins that black tea does. Both types can contribute antioxidants to your diet and have been shown to have antiviral, anti-inflammatory, detoxifying and immune-stimulating effects.

Green tea, however, is considered to have originated in China. It is said that even today the word “tea” in China refers only to green tea, not to the general category of tea as it does in the West. China’s Yunnan province is considered to be the original home of the Camellia sinensis plant species. In fact, 260 of the world’s 380+ varieties of tea can be found in Yunnan.

The leaves are used to make a herbal tea that is called by the names: rooibos, bush tea (especially in Southern Africa), or redbush tea (predominantly in Great Britain). The tea has been popular in Southern Africa for generations, but is now consumed in many countries worldwide. It is sometimes spelled rooibosch in accordance with the original Dutch. The tea has a taste and color somewhat similar to hibiscus tea, or an earthy flavor like yerba mate.
Another benefit of green tea it’s is lower in caffeine than most other teas, so you may be able to drink the five cups a day that lowered psychological stress in a large group of Japanese people in a recent study done at Sendai’s Tohoku University Graduate School of Medicine. The researchers didn’t identify any particular component of green tea that might have been soothing, but animal studies suggest that one compound, EGCC, had both sedative and hypnotic effects that tamp down the body’s production of stress chemicals. In Canada, green tea is defined as a dry-based mixture and the sale of it is regulated by the Canadian Food Inspection Agency (CFIA). It is one of the foods for which a standard of identity is specified according to the Food and Drug Regulations. It should contain not less than 33% water-soluble extractive (determined by official method FO-37 which is the determination of water-soluble extractive in tea) and the total ash should between 4% to 7%.[92]
Rooibos or 'red bush' from South Africa is found to be a very potent variety of red tea prepared from the leaves of the herb Aspalathus linearis. Indigenous to the Cape of Good Hope region of South Africa, Rooibos is the only red tea that undergoes a fermentation process similar to black tea. Fermentation turns the green leaves into a garnet colour and lends a very sweet flavor. Rooibos endowed with a very high magnesium ('Nature's tranquilizer') component, acts as a natural adaptogen i.e., that which helps the body adapt to stress.

All commercial tea produced in Japan today is green tea,[54] though for a brief period black tea was also produced in the late 19th and early 20th centuries. Japanese tea production is heavily mechanized, and is characterized by the use of modern technology and processes to improve yields and reduce labor. Because of the high cost of labor in Japan, only the highest quality teas are plucked and processed by hand in the traditional fashion.[55]

In Canada, green tea is defined as a dry-based mixture and the sale of it is regulated by the Canadian Food Inspection Agency (CFIA). It is one of the foods for which a standard of identity is specified according to the Food and Drug Regulations. It should contain not less than 33% water-soluble extractive (determined by official method FO-37 which is the determination of water-soluble extractive in tea) and the total ash should between 4% to 7%.[92]

In 1994, Burke International registered the name "Rooibos" with the US Patent and Trademark Office, thus establishing a monopoly on the name in the United States at a time when it was virtually unknown there. When the plant later entered more widespread use, Burke demanded that companies either pay fees for use of the name, or cease its use. In 2005, the American Herbal Products Association and a number of import companies succeeded in defeating the trademark through petitions and lawsuits; after losing one of the cases, Burke surrendered the name to the public domain.[13]